The primary purpose of using the PAS with Diastase staining procedure is to differentiate glycogen from other PAS positive elements such as mucin that may be present in the tissue sample. Mucin can be specifically identified in certain tissue samples using the PAS staining procedure only if the glycogen (which is also PAS-positive) is digested with diastase and washed out.
Several enzyme deficiencies can be diagnosed through the analysis of glycogen deposits in the liver.
The PAS with Diastase staining procedure can also be used to differentiate glycogen granules from other granules in various tumor types.
